# 描述
# 把一个字符串中所有出现的大写字母都替换成小写字母，同时把小写字母替换成大写字母。
#
# 输入
# 输入一行：待互换的字符串。
# 输出
# 输出一行：完成互换的字符串（字符串长度小于80）。
# 样例输入
# If so, you already have a Google Account. You can sign in on the right.
# 样例输出
# iF SO, YOU ALREADY HAVE A gOOGLE aCCOUNT. yOU CAN SIGN IN ON THE RIGHT.

s = input()
a = ""

for i in range(len(s)):
    if s[i].isupper():
        a += s[i].lower()
    elif s[i].islower():
        a += s[i].upper()
    else:
        a += s[i]
print(a)